Electromagnetically actuated switch



Filed July 16, 1956 4 Sheets-Sheet IL U .4 i Q [:34 6

Jan. 24, 1961 o. DEISSLER ELECTROMAGNETICALLY ACTUATED SWITCH 4Sheets-Sheet 2 Filed July 16, 1956 Jan. 24, 1961 o. DEISSLERELECTROMAGNETICALLY ACTUATED SWITCH 4 Sheets-Sheet 4 Filed July 16, 1956Unite States Patent 2,969,444 ELECTROMAGNETICALLY ACTUATED SWITCH OttoDeissler, Gummersbach-Niedernhagen, Germany Filed July 16, 1956, Ser.No. 598,160

24 Claims. (Cl. 200-87) The invention relates to an electromagneticallyactuated switch or contactor designed to serve asa control relay, powerrelay or remote-control motor-protection switch where a thermal relay issubsequently in stalled.

Under the invention, construction is such that with exception of theterminal screws of the main and auxiliary contacts, screw joints havebeen eliminated, which makes for economical production. Both coil andmain and auxiliary contacts may be replaced without the use of toolsafter their electrical connections have been released. Moreover, thecondition of the contacts may be checked without the aid of tools.Furthermore, all connections of the main and auxiliary contacts and ofthe coil are accessible from the front of the contactor.

The device utilizes a pivotally mounted bell crank lever, one of whosearms supports the moving main contacts and actuates spring biasedauxiliary contacts, while the other arm supports the armature of themagnet, whose core, around one leg of which the coil is wound, is placedparallel with and above the main contacts. Since the bell crank leverpivots, the device may be mounted in any position, with friction largelyeliminated. The pressure springs of the auxiliary contacts also act uponthe bell crank lever, so that regardless of the position of theelectromagnetically actuated switch the angle lever is brought into itsnormal position when the pull coil is disconnected.

To provide a favorable ratio between magnet pull and contact pressure ofauxiliary contacts as well as pressure upon the bell crank lever, themovable contacts of the auxiliary contacts are actuated by means of arocking lever which translates the long stroke of the bell crank leverarm acting on the auxiliary movable contacts into the short strokerequired by the auxiliary contacts.

The movable main contacts are pivotally mounted on the bell crank leverand are formed as a bridge across two stationary contacts for each pole.The stationary contacts are located in quenching chambers where thepoints of contact are encircled by rings made of iron or a similarmaterial shaped in such a way that the electric arc is drawn into thechamber, where it is cooled, broken down and rapidly destroyed. Forcleaning or replacement of the stationary main contacts, the quenchingchambers containing the fixed main contacts are removable from the lowersection of the device by means of a sliding motion, but are normallysecured in operating position by a leaf spring detent. In operatingposition, the stationary main contacts are prevented from slidinginwardly by a stop in the lower section of'the device as well as by theterminal screw. For replacement, each fixed contact is pulled out of itsrespective quenching chamber, without the use of tools, after removal ofthe terminal screws.

The quenching chambers are constructed in such a way that two stationarycontacts may be inserted one on top of the other, with a certainseparation between 2,969,444 Patented Jan. 24, 1961 the two, so that onefixed contact is at the top and the other at the bottom of the quenchingchamber. Similarly, the movable-contact holder will accommodate twomoving contacts spaced to correspond with the stationary contacts sothat the compression contact spring is located between the two movablecontacts. In the normal position, with the pull coil cut out of thecircuit, the upper main contacts will then be closed, while uponenergizing the coil they are opened and the lower ones are closed.

The movable-contact holders are mounted on the bell crank lever byspecially shaped leaf springs fixing the movable contacts on the leverarm. The securing of the contacts is effected merely by inserting thesprings at a degree angle to the movable contact bridge and thereafterturning the spring to a position parallel with the main contacts.

The fixed auxiliary contacts are mounted in a removable block. A movableblock is slidably mounted in the removable block and carries the movableauxiliary contacts. The fixed auxiliary contacts may be set in eachremovable block, without the aid of tools so as to establish two singlepole normally closed circuits, two single pole normally open circuits orone normally closed and one normally open circuit.

The device is so encased and covered by the lid in such a way thatcoarse dust cannot penetrate into its inside. The lid is so constructedand fitted that when viewed from the front the bell crank lever willindicate whether the device is switched on or olf. For this purpose, thelever bears the marking off, which disappears under the lid and becomesinvisible when the device is connected. The lid also serves as a limitstop for the bell crank lever, aside from holding the plate showing themodel number, manufacturers name and ratings, with a'blank space foridentification of the device.

The lid is hinged and attached to the hinge pin is the magnet-coreholder which supports magnet core and pull coil. A spiral spring forcesthe pull coil against a detent in the lid. In operating position, thelid rests on the lower section, enclosing magnet core and coil as wellas armature. To replace the coil, the lid is raised and the coil forcedagainst the spiral spring so as to swing magnet core and coil clear ofthe detent. After releasing the coil connections, the coil is pulled offthe leg of the magnet.

The complete assembly of the electromagnetically actuated switch ismounted by means of steel rails fixed to the assembly which may bescrewed or otherwise secured to supporting structure.

A thermal relay used, for example, to protect a motor against overloadsmay be attached to the base of the device in such a way that after themain contacts have been brought out for control purposes, the bell cranklever rests above it. Therefore, the thermal relay will not requireextra space.

The several features of the invention will become more readily apparentfrom the following detailed description taken in conjunction with theaccompanying drawings in which: i

Fig. l is an elevational view taken in front of the invention;

Fig. 2 is a side elevational view thereof;

Fig. 3 is a top plan view thereof;

Fig. 4 is a bottom plan view thereof;

Fig. 5 is a cross sectional view taken along lines 5-5 of Fig. 3;

Fig. 6 is a view similar to that of Fig. 5 showing the contacts inclosed position;

Fig. 7 is an elevational view taken from the front of the invention withthe covering lid removed;

Fig. 8 is an elevational view partly in section showing the elements inpartially disassembled relation;

Fig. 9 is a fragmentary view partly in section of an alternativeembodiment; and

Fig. 10 is a fragmentary view partly in section showing an alternativemounting of the main contacts.

Referring to Figs. 1 through 4, the contactor of the present inventionhas a housing including lower section or body portion 1 which is in theform of a rectangular box open at the front and bottom faces thereof andto which are fixed mounting rails 2. The mounting rails have aperturesin the ends thereof by which the whole device may be mounted to asupporting structure. The lower section 1 is enclosed by a cover lid 10which is pivotally mounted to the lower section on a hinge pin 11. Thelower section 1 has a leaf spring 12 (Fig. 4) the leaf spring beingslotted at its free end to receive a projection 13 integral with the lid10. The leaf spring 12 mounted on each side of the contactor secures thelid in the closed position shown in Figs. 1 to 4 but permi-ts the lid tobe swung easily to an open position as shown in Fig. 8. The lid 10prevents the penetration of the contactor by coarse dust. Lid 10 has arecess 17 in which a plate identifying model, manufacturer and ratingsmay be disposed.

As best shown in Figs. and 6, the lower section has trackways whichslidably receive main stationary contact blocks 4, the blocks beingsecured to the lower section by leaf springs 3. Stationary contacts 5are mounted on the blocks 4 and are fitted with solderless connectors 6by which they may be connected into a support. The inner end portions ofthe blocks 4 engage lugs 18 projecting from the lower section 1 to limitinward movement of the blocks.

The stationary contacts 5 have contact tips 19 which are disposed withinarc quenching chambers. The are quenching chambers are formed by threespaced U-shaped iron strips 20 which are so related to the contact tips19 that an electric arc is drawn into the chamber formed by the strips.

The lower section 1 also slidably receives removable auxiliary contactblocks 7. As shown in Fig. 3, a pair of blocks is received in the upperportion of the casing, each pair having two sets of contacts of the typeshown in Figs. 5 and 6. The removable contact block has a slidable block29 mounted therein, the slidable block 29 carrying movable contactsindicated at 30. The movable auxiliary contacts 30 are slidably mountedin the block 29 and are urged toward their respective stationaryauxiliary contacts by means of compression springs 31 which are locatedbetween the slidable block 29 and the movable contacts 30.

The stationary block 7 has contacts 8 fixed therein, the contacts 8being provided with terminals by which auxiliary line connections can bemade to the contacts. The slidable block 29 is urged by a compressionspring 37 toward the main stationary contacts 5. To operate theauxiliary contacts the block 29 is movable in the opposite direction bya lever 32 pivoted about a fulcrum bearing 34, the fulcrum 34 beingfixed in the contact block 7. One arm 33 of the lever 32 bears againstthe slidable block 29, while the other arm 35 is operably engaged by abell crank lever 15 pivoted to the lower section 1 on a pin 14 fixed inthe lower section by the fixed ends of leaf springs 13. The arm 35 isbifurcated to permit main movable contacts to pass by.

The stationary contacts 8 are mounted in slots in the contact block 7and are adapted to be removed and disposed in different positions so asto be either normally open or normally closed, depending upon therequirements of the particular circuit with which the contactor is used.

One arm of the bell crank lever 15 supports a magnetic armature 21 in aslot by means of a removable pin 22. As can be seen from Figs. 5 and 6,there is a space between the armature 21 and the bell crank lever 15,the space permitting slight pivotal movement of the armature about thepin 22 to permit the armature to adjust itself to the magnetic core towhich it is drawn. A strip of material 23 is disposed in that space todamp the armature.

The other arm of bell crank lever 15 receives a pin 24 terminated in anarcuate member 24A on which a movable contact bar or bridge 25 ispivotally and slidably mounted. The contact bridge 25 has precious metaltips 26 which are engageable with the stationary contact tips 19 toclose the circuit between the tips.

A compression spring 27 is located between the contact bridge 25 and thearm of the bell crank lever to provide pressure of engagement of thecontact tips 26 with the stationary contact tips 19. The contact bridge25 can rotate or pivot with respect to the member 24A so as to permitprecise engagement of the tips 26 with the stationary tips 19, thespring 27 frictionally holding the bridge 25 in the proper position ofalignment with respect to the stationary tips 19.

The pin 24 to which the contact bridge 25 is secured is mounted on thearm of hell crank lever 15 by means of a leaf spring 28 which is fittedon the end of the pin in a direction perpendicular to the contact bridgeand then swung through to the position shown in Figs. 5 and 6 to secureeach contact bridge in position.

The end of the bell crank lever arm adjacent the contact bridge 25 has aprojection 36 which is engageable with the arm 35 of the lever 32 bywhich the auxiliary contacts are operated as described above.

Referring to Figs. 5 and 6, the hinge pin 11 by which the cover lid 10is pivotally supported to the lower section 1 also supports a channelshaped holder 38 by which a magnetic core 39 is mounted on the lid. Acoil 40 is slidably mounted on the core 39. A helical compression spring41 engaging a flange on support 38 at one end thereof has its other endin engagement with the coil 40 to force the coil against a projection 42on the lid 10, whereby the coil and magnetic core are held in place. Thecoil is removable by pivoting the core and coil assembly away from theprojection 42 so that the coil may be slid off the core 39.

The edge of the cover lid 10 remote from its pivot axis at 11 has aprojection 44 which is engageable by a projection 43 on the bell cranklever 15 to prevent the bell crank lever from swinging farther than theposition shown in Fig. 5. The edge of the angle lever bears a markingoff which is visible through an opening 16 in the lid 10 when the coil49 is de-energized.

An alternative form of the main contacts is illustrated in Fig. 9. Inthis form of the invention, an additional fixed contact 45 is mounted inspaced relation to the stationary contact 5 and within the arc quenchingchamber. A second contact bridge 46 is mounted on the pin 24. When themagnetic coil is energized, contact tips 26 will be moved intoengagement with contact tips 19. When the coil 40 is de-energized, thebell crank lever 15 moves to the position illustrated in Fig. 9 in whichthe circuit at contact tips 19 and 26 is opened and the circuit acrosscontacts 45 is closed.

Another form of the invention is shown in Fig. 10. In accordance withFig. 10, an extended shaft 47 is mounted on the side of the contactorand carries with it arms 15 to which are mounted additional contactbridges 25. Rotation of the bell crank lever will cause a rotation ofthe shaft 47 and effect the closing of the additional contacts at thesite of the contactor, the only requirement being that the contactpressure provided by the core and coil besufiiciently great to provideadequate contact pressure.

Fig. 8 shows the contactor with the lid 10 swung to open position andthe bell crank lever 15 swung to its open position. As seen from thisview, it is possible to mount a small thermal relay or the like 48immediately adjacent the contactor for the location and design of thebell crank lever 15 is such as to permit its operation with outinterference from such a thermal relay.

It can be appreciated from the foregoing discussion that the contactoradmits of manufacture by first assembling the sub-assemblies, such asthe lid 10 with its core and coil, the auxiliary contact block, the bellcrank lever and the slidable main contacts. Once assembled, thesub-assemblies may be quickly inserted or mounted on the lower section 1so that the parts appear as shown in Fig. 8. When the bell crank lever15 is swung to its operating position as shown in Fig. 5, the cover lid10 may be closed as shown in Fig. 5, and secured in closed position bythe leaf springs 12 which engage projections 13 on the lid as shown inFig. 4. In the closed assembled position, the coil leads are secured toconnectors 9 as illustrated in Fig. 9 where they are accessible forready connection to appropriate circuits.

As illustrated in Fig. 5, the bell crank lever 15 is maintained in theposition shown by the pressure of spring 37 acting on lever 32 throughslidable auxiliary contact block 29. The contact bridge 25 with its tips26 are moved into engagement with stationary contact tips 19 uponenergization of the coil 40. When coil 40 is energized, the bell cranklever 15 is caused by the movement of the armature 21 toward the core 39to move to the position of Fig. 6. The movement from the position ofFig. 5 to the position of Fig. 6 is against the pressure of thecompression spring 37.

Spring 37 is compressed by the lever 32 acting on slidable block 29, themovement of the slidable block 29 causing the operation of the auxiliarycontacts.

I claim:

1. A switch comprising a housing having a removable front cover, fixedcontacts mounted on the rear vertical surface of said housing, a bellcrank lever and having a vertical and horizontal leg pivotally mountedin said housing, movable contacts fixed to the end of said vertical legand engageable with said fixed contacts by movement substantiallyperpendicular to said surface, a coil mounted in the front cover of saidhousing and cooperating with an armature on the horizontal leg of saidlever, whereby energization of said coil will close said contacts.

2. A contact having two tips for bridging a second pair of contact tipscomprising, a bar having a contact tip at each end, said bar having acircular portion intermediate the ends thereof, a mounting having atleast one surface cooperating with said circular portion, and meansresiliently holding said circular portion in frictional engagement withsaid cooperating surface, whereby said contact bar may rotate about saidmounting and remain in its rotated position to provide simultaneousengagement of said contact tips.

3. A contact comprising, a contact bar having a contact tip at each endadapted to bridge two spaced contact tips, a movable member for movingsaid bar into engagement with said contact tips, and means for pivotallyand frictionally mounting said bar to said member to permit said bar torotate at least in the plane defined by said pairs of. contact tips andto remain in the position to which it has been rotated.

4. A contact according to claim 3 and spring means biasing said arm intoits pivotal mounting.

5. A magnetically operated switch comprising a rectangular box open atthe front and bottom faces, a bell crank lever pivoted at the bottom ofsaid box and having an armature fixed to one end of a normallyhorizontal leg of said lever, vertical trackways in the rear of saidbox, fixed contacts slidable into position in said trackways, movablecontacts mounted on the normally vertical leg of said lever andengageable with said fixed contacts, a removable front cover for saidbox, and an electromagnet mounted in 'saidicover and adapted tocooperate with said armatureto operate said switch.

6. An electromagnetically operated switch comprising, a box, fixedcontacts mounted in said box, movable contacts mounted on a contactcarrier, means mo-vably mounting said carrier in said box whereby saidcontacts can be engaged and disengaged, an armature mounted on saidcarrier, a cover movable between open and closed positions for said box,and an electromagnet mounted on said cover, said electromagnetcooperating with said armature, when said cover is in closed position,to operate said carrier, and when said cover is in open position saidelectromagnet being exposed for repairing operations.

7. A magnetically operated switch comprising a re ctangular box open atthe front and bottom faces, a bell crank lever pivoted at the bottom ofsaid box and having an armature fixed to one end of a normallyhorizontal leg of said lever, vertical trackways in the rear of saidbox, fixed contacts slidable into position in said trackways, movablecontacts mounted on the normally vertical leg of said lever andengageable with said fixed contacts, a removable front cover for saidbox, an electromagnet mounted in said cover and adapted to cooperatewith said armature to operate said switch, trackways formed in the topof said box, and at least one auxiliary contact slidable in saidtrackways.

8. A switch according to claim 7 further comprising an operating leverdepending from said auxiliary contact and disposed adjacent saidnormally vertical leg, said operating lever being moved by said verticalleg when said electromagnet is energized to operate said auxiliarycontacts simultaneously with said first mentioned contacts.

9. A magnetically operated switch comprising a rectangular box open atthe front and bottom faces, a. bell crank lever pivoted at the bottom ofsaid box and having an armature fixed to one end of a normallyhorizontal leg of said lever, vertical trackways in the rear of saidbox, fixed contacts slidable into position'in said trackways, movablecontacts mounted on the normally verti cal leg of said lever andengageable with said fixed contacts, a removable front cover for saidbox, an electro magnet mounted in said cover and adapted to cooperatewith said armature to operate said switch, trackways formed in the topof said box, at least one auxiliary contact slidable in said trackways,said auxiliary contacts forming the top of said box, and said normallyhorizontal leg of said lever extending between the vertical sides ofsaid box to form the bottom of said box.

10. A magnetically operated switch comprising a rectangular box open atthe front and bottom faces, a bell crank lever pivoted at the bottom ofsaid box and having an armature fixed to one end of a normallyhorizontal leg of said lever, fixed contacts mounted in the rear of saidbox, movable contacts mounted on the normally vertical leg of said leverand engageable with said fixed contacts, an electromagnet mounted in thefront of said box and adapted to cooperate with said armature to operatesaid switch, auxiliary contacts mounted in the top of said box, anoperating lever depending from said auxiliary contact and engaging theend. portion of said normally vertical leg, and spring means urging saidoperating lever against said vertical leg in a direction to hold saidleg away from said fixed contacts.

11. A switch according to claim 10 in which said operating lever isbifurcated and said movable contacts pass between the legs of saidoperating lever.

12. A magnetically operated switch comprising a rectangular box open atthe front and bottom faces, a bell crank lever pivoted at the bottom ofsaid box and having an armature fixed to one end of a normallyhorizontal leg of said lever, vertical trackways in the rear of saidbox, fixed contacts slidable into position in said trackways, movablecontacts mounted on the normally vertical leg of said lever andengageable with said fixed contacts, a removable front cover for saidbox, means pivoting said cover to the top of said box, and anelectromagnet mounted in said cover and adapted to cooperate with saidarmature to operate said switch, said bell crank lever being pivotableapproximately 90 toward the front of said box when said cover is pivotedaway from said box, said cover being adapted to positively block saidswitch from closing operation when said lever has been pivoted to itsposition toward the front of said box.

13. A magnetically operated switch comprising a rectangular box open atthe front and bottom faces, a bell crank lever pivoted at the bottom ofsaid box and having a transverse slot across one end of the horizontalleg thereof, an armature disposed in the slot in said horizontal leg,and a pin removably locking said armature in said slot, verticaltrackways in the rear of said box, fixed contacts slidable into positionin said trackways, movable contacts mounted on the normally vertical legof said lever and engageable with said fixed contacts, a removable frontcover for said box, and an electromagnet mounted in said cover andadapted to cooperate with said armature to operate said switch.

14. A magnetically operated switch comprising a rectangular box open atthe front and bottom faces, a bell crank lever pivoted at the bottom ofsaid box and having an armature fixed to one end of a normallyhorizontal leg of said lever, vertical trackways in the rear of saidbox, fixed contacts slidable into position in said trackways, movablecontacts mounted on the normally vertical leg of said lever andengageable with said fixed contacts, a removable front cover for saidbox, means pivoting said cover to the top of said box, an electromagnetmounted in said cover and adapted to cooperate with said armature tooperate said switch, said bell crank lever being pivotable approximately90 toward the front of said box when said cover is pivoted away fromsaid box, said cover being adapted to positively block said switch fromclosing operation when said lever has been pivoted to its positiontoward the front of said box, said movable contact comprising a contactbar having a contact tip at each end adapted to bridge said two spacedfixed contacts, said bar having a circular portion intermediate the endsthereof, a mounting on said lever having at least one surfacecooperating with said circular portion, and means resiliently holdingsaid circular portion in engagement with said cooperating surface,whereby said contact bar may rotate about said mounting to providesimultaneous engagement of said fixed contacts.

15. In a switch having a housing and an electromagnetically operatedarmature for carrying contacts, a removable cover and magnetconstruction for said housing comprising a magnetic core pivotallymounted in said housing cover, said core having at least one open endedleg, a winding slidably mounted on said leg, and slidably removabletherefrom when said core is pivoted away from said cover, and means forsecuring said core and winding to said cover.

16. In a switch having a housing and an electromagnetically operatedarmature for carrying contacts, a removable cover and magnetconstruction for said housing comprising a magnetic core pivotallymounted in said housing cover, said core having at least one leg open atan end remote from the pivotal mounting, a winding slidably mounted onsaid leg and slidably removable therefrom when said core is pivoted awayfrom said cover, and cooperating latching means on said cover andwinding for securing said core and winding on said cover.

17. A switch according to claim 16 and spring means urging said windinginto latched position.

18. In a switch having a housing and an electromagnetically operatedarmature for carrying contacts, a cover, a hinge pin extending throughthe top portion of said cover for pivotally mounting said cover on saidhousing, and a magnetic core carried by said cover and pivotally mountedon said hinge pin.

19. A switch according to claim 18, and a pair of slots at the topportion of said housing for removably receiving said hinge pin, wherebysaid cover may be removably and pivotally mounted on said housing.

20. In a switch having a housing, an electromagnetically operatedarmature for carrying contacts com prising a bell crank lever pivotallymounted in said housing, contacts mounted on one leg of said lever, anarmature bar mounted on the other leg of said lever, a cover for saidhousing mounted generally perpendicular to said other leg, an E-shapedcore carried by said cover and having the open ends of the legs of the Eadjacent said bar, and a winding slidably mounted on the middle leg ofsaid E.

21. A magnetically operated switch comprfsng a rectangular box open atthe front and bottom faces, a bell crank lever pivoted at the bottom ofsaid box and having an armature fixed to one end of a normallyhorizontal leg of said lever, vertical trackways in the rear of saidbox, fixed contacts slidable into position in said trackways, springlatch means securing said fixed contacts in position, and movablecontacts mounted on the normally vertical leg of said lever andengageable with said fixed contacts.

22. A switch according to claim 21 in which each said trackways is adove tail groove, each said fixed contacts having a complementaryprojection, and said spring latch means comprising a leaf spring lyingin said groove and having a projection at one end thereof engageablewith the end of said complementary projection.

23. A switch according to claim 8 in which said operating lever isspring biased to resist movement of the vertical leg of said bell cranklever, thereby decelerating the contact closing movement of said bellcrank lever.

24. A magnetically operated switch comprising a housing, fixed contactsin said housing, a magnetically operated armature movably mounted insaid housing and carrying contacts adjacent said fixed contacts,electromagnetically operated means for moving said armature in a closingdirection to effect the engagement of said armature contacts with saidfixed contacts, an auxiliary contact mounted in said housing, an operatng member on said auxiliary contact engageable by said armature tooperate said auxiliary contact, and spring means biasing said operatingmember to decelerate the movement of said armature in closing direction.

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